RICHMOND, Va.—An official of the Virginia Workers' Compensation Commission has vacated a $200-per-day fine on Facebook for failing to reveal information from a subscriber's account.

Virginia imposed the fine Aug. 28 after Palo Alto, Calif.-based Facebook Inc. did not respond to a workers comp defense attorney's subpoena seeking information about an employee for Manassas, Va.-based Colgan Air Inc., said Chief Deputy Commissioner James J. Szablewicz.

Facebook responded later and argued that the federal Electronics Communications Privacy Act prohibited it from responding to the subpoena. A deputy commissioner agreed and vacated the $200-per-day fine, Mr. Szablewicz said. Facebook also argued that courts have ruled that the U.S. law prohibits social networking sites from revealing subscribers' information—even in the face of a subpoena.

The case reportedly involved the airline's attempt to obtain vacation photos of an employee to counter a workers comp claim for a back injury.